KR20100089824A - Dye-sensitized solar cell and manufacturing method of same - Google Patents

Abstract

Provided are a dye-sensitized solar cell which can be easily manufactured, has high power take-out efficiency, and is suitable for large size, and a manufacturing method thereof. The dye-sensitized solar cell includes a substrate having a transparent substrate 12, a porous semiconductor layer 14 adsorbing a dye, a conductive metal film 16, and a conductive film, and the conductive metal film 16 and the conductive film. The electrolyte is provided between the substrates provided. In the conductive metal film 16, a plurality of through holes having a deep hole shape are irregularly formed. The conductive metal film 16 is electrically connected to an external electrode. The through hole forms the conductive metal film 26 on the fine particle layer formed by arranging the fine particles 28 having the shape anisotropy on the porous semiconductor layer 14, and then the fine particle layer is heated by heating or solvent cleaning. It is obtained by disappearing.

Description

Dye-sensitized solar cell and its manufacturing method {DYE-SENSITIZED SOLAR CELL AND MANUFACTURING METHOD OF SAME}

TECHNICAL FIELD This invention relates to a dye-sensitized solar cell and its manufacturing method.

Dye-sensitized solar cells are called wet solar cells or Graetzel cells and are characterized by having an electrochemical cell structure represented by an iodine solution without using a silicon semiconductor. Specifically, a porous semiconductor layer such as a titanium dioxide layer formed by baking a titanium dioxide powder or the like on a transparent conductive glass plate (a transparent substrate on which a transparent conductive film is laminated) and adsorbing a dye thereon and a conductive glass plate (conductive substrate) It has the simple structure which arrange | positioned the iodine solution etc. as electrolyte solution between the counter electrode which consists of these.

Dye-sensitized solar cells are attracting attention as low-cost solar cells because their materials are inexpensive and do not require large-scale equipment for their production.

Dye-sensitized solar cells are required to further improve the conversion efficiency of solar light, and have been examined from various viewpoints.

As one of them, in order to improve the power extraction efficiency by improving the conductivity of the electrode, omitting the transparent conductive film normally formed on the transparent substrate provided on the light incident side is examined. This is particularly important when increasing the size of solar cells.

For example, a transparent conductive film may be omitted, and a TiO ₂ porous semiconductor layer adsorbed with a dye may be directly provided on a transparent substrate, and a porous thin electrode formed by sputtering Ti on the surface of the porous semiconductor layer may be formed of a collecting electrode ( There is disclosed a dye-sensitized solar cell which is made of a spinner (see Non-Patent Document 1). The solar cell conversion efficiency of this battery is reported to be 3.6%.

For example, the photoelectric conversion element of the structure which has the laminated part which contains a semiconductor fine particle layer, a metal network, a charge transfer layer, and a counter electrode in this order on a glass substrate, and the metal network and the charge transfer layer directly contacted. Is disclosed (see Patent Document 1).

Japanese Patent Publication No. 2007-73505

 J. M. Kroon, et al., Nanocrystalline Dye-sensitized Solar Cells Having Maximum Performance, Prog. Photovolt, Wiley InterScience, 2006

However, although Non-Patent Document 1 does not mention the thickness, aperture ratio, or the like of the Ti thin film, when the thickness of the Ti thin film formed by sputtering is extremely thin, for example, about 20 nm, the surface of the porous semiconductor layer Although a hole may be formed in the Ti thin film formed on the unevenness of the TiO ₂ particles, there is a concern that the area resistance (sheet resistance) of the Ti thin film becomes large, which may not lead to a significant improvement in the power extraction efficiency. On the other hand, when the thickness of the Ti thin film is made to be thick, for example, several hundred nm, in order to reduce the area resistance of the Ti thin film, no holes are formed in the Ti thin film, and penetration of the electrolyte into the porous semiconductor layer is prevented, thereby making it a solar cell. It may not function.

Moreover, the thing of patent document 1 is complicated as a manufacturing method, and there exists a possibility that manufacturing cost may become high.

This invention is made | formed in view of said subject, Comprising: It aims at providing the dye-sensitized solar cell which can be manufactured easily, is high in power take-out efficiency, and suitable for enlargement, and its manufacturing method.

The dye-sensitized solar cell according to the present invention is disposed on a transparent substrate, a porous semiconductor layer adsorbed with a dye disposed on the transparent substrate, a surface inside the porous semiconductor layer or on the opposite side to the transparent substrate, A plurality of through-holes having a deep hole shape are irregularly formed, and a conductive metal film electrically connected to an external electrode, and a conductive substrate provided to face the transparent substrate, are provided between the conductive metal film and the conductive substrate. It is characterized by having an electrolyte.

The dye-sensitized solar cell according to the present invention is preferably characterized in that the thickness of the conductive metal film is 100 nm or more.

In the dye-sensitized solar cell according to the present invention, the material of the conductive metal film is preferably a corrosion-resistant metal.

Further, the dye-sensitized solar cell according to the present invention is preferably characterized in that the corrosion resistant metal is one or two or more or a compound thereof selected from tungsten, titanium and nickel.

Moreover, the manufacturing method of the dye-sensitized solar cell which concerns on this invention is a manufacturing method of said dye-sensitized solar cell, Comprising: The microparticles | fine-particles which have a shape anisotropy which can be removed by heating or a solvent wash are arrange | positioned on a porous semiconductor layer. And a fine particle layer forming step of forming a fine particle layer, a conductive metal film forming step of forming a conductive metal film on the fine particle layer, and a fine particle layer disappearing step of disappearing the fine particle layer by heating or solvent washing. It features.

Moreover, the manufacturing method of the dye-sensitized solar cell which concerns on this invention is a manufacturing method of said dye-sensitized solar cell, The mixed layer of a porous semiconductor material and microparticles | fine-particles which have a shape anisotropy which can be removed by heating or a solvent wash | cleaning. And a mixed layer forming step of forming a conductive metal film on the porous semiconductor layer, a conductive metal film forming step of forming a conductive metal film on the surface of the mixed layer, and a fine particle layer disappearing step of dissipating the fine particles by heating or solvent washing. It features.

Moreover, the manufacturing method of the dye-sensitized solar cell which concerns on this invention is a manufacturing method of said dye-sensitized solar cell, Comprising: The mixed layer of electroconductive metal and microparticles | fine-particles which have a shape anisotropy which can be removed by heating or a solvent wash is provided. It is characterized by having the mixed-layer formation process formed on a porous semiconductor layer, and the fine-particle layer disappearance process which loses the said microparticles | fine-particles by heating or a solvent washing | cleaning.

Moreover, the manufacturing method of the dye-sensitized solar cell concerning this invention, Preferably, it has a porous semiconductor layer lamination process which forms the porous semiconductor layer different from the said porous semiconductor layer on the surface of the said conductive metal film further, It is characterized by the above-mentioned. .

Moreover, the manufacturing method of the dye-sensitized solar cell concerning this invention, Preferably, the microparticles | fine-particles which have said shape anisotropy are microparticles or needle-like microparticles | fine-particles which have many legs which make the apex of a polyhedron the tip.

In the dye-sensitized solar cell according to the present invention, a transparent conductive film, which is usually provided on a transparent substrate, is omitted, and instead of being disposed on the inside of the porous semiconductor layer or on the surface opposite to the transparent substrate, Since the through-holes are irregularly formed and a conductive metal film electrically connected to the external electrode is provided, the dye-sensitized mode suitable for the enlargement can be easily manufactured, the power extraction efficiency is high, and especially the thickness of the conductive metal film is thickened. I can do it with a battery.

Moreover, the manufacturing method of the dye-sensitized solar cell which concerns on this invention is a manufacturing method of said dye-sensitized solar cell, Comprising: Formation of the hole of a conductive metal film with microparticles | fine-particles which have a shape anisotropy which can be removed by heating or a solvent wash | cleaning. Since it is used for, the said dye-sensitized solar cell can be obtained very suitably.

FIG. 1: is a figure which shows typically the cross-sectional structure of the dye-sensitized solar cell which concerns on this embodiment.
FIG. 2A is a schematic diagram of a battery member structure for explaining a manufacturing step of the manufacturing method of the dye-sensitized solar cell according to the present embodiment, and for illustrating the porous semiconductor layer forming step. FIG.
It is a schematic diagram of a battery member structure for demonstrating the manufacturing process of the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment, and is a figure for demonstrating a fine particle layer formation process.
FIG. 2C is a schematic diagram of a battery member structure for explaining a manufacturing step of the method for manufacturing the dye-sensitized solar cell according to the present embodiment, and for illustrating the conductive metal film forming step. FIG.
It is a schematic diagram of a battery member structure for demonstrating the manufacturing process of the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment, and is a figure for demonstrating a microparticle layer disappearance process.
The pigment | dye adsorption state of titanium dioxide at the time of using the porous Ti electrode of Example 1 for FIG. The dye adsorption state of the glass substrate in the case of forming is shown.
4 is a diagram showing the relationship between the sheet resistance and the thickness of the Ti film of the dye-sensitized solar cell.
5 is a diagram illustrating a relationship between voltage and current density of a dye-sensitized solar cell.

A very suitable embodiment of the dye-sensitized solar cell and the method for producing the same according to the present invention will be described below with reference to the drawings.

For example, as schematically shown in FIG. 1, in the dye-sensitized solar cell 10 according to the present embodiment, the porous semiconductor layer adsorbed the transparent substrate 12 and the dye disposed on the transparent substrate 12. (14), a conductive metal film (16) disposed on the surface of the porous semiconductor layer (14) opposite to the transparent substrate (12), and a conductive film (18) provided opposite the transparent substrate (12). One substrate 20 (conductive substrate) is provided. The electrolyte 22 is provided between the conductive metal film 16 and the substrate 20 provided with the conductive film 18. Reference numeral 23 in FIG. 1 denotes a spacer provided to seal the electrolyte 22 in the battery.

In the conductive metal film 16, a plurality of through holes 24 having a deep hole shape are irregularly formed. Here, the deep hole-shaped through hole 24 is such that even when the conductive metal film 16 is thick, a hole having a relatively small diameter has a deep depth enough to reliably penetrate the conductive metal film 16. The meaning of a hole, for example, refers to a long cylindrical hole having an depth dimension of several times or several tens of times the diameter of the hole.

The conductive metal film 16 is formed of, for example, the same material as the conductive metal film 16, and is provided to an external electrode (collecting electrode) 26 provided on the periphery of the transparent substrate 12. Electrically connected. In addition, the external electrode 26 may be provided at a suitable position independently of the transparent substrate 12. In addition, the conductive metal film 16 may be provided inside the porous semiconductor layer 14. Alternatively, a plurality of conductive metal films 20 may be formed alternately with the porous semiconductor layer.

The conductive metal film 16 preferably does not have a thermal history of at least the temperature required for firing the material of the porous semiconductor layer 14, and is sufficiently lower than 500 ° C, more preferably about 200 ° C or less. The thing which has a thing or what does not go through a heating process substantially. In addition, the porous semiconductor layer 14 preferably has a hole communicating with the hole passing through the conductive metal film 16.

The transparent substrate 12 and the substrate 20 may be, for example, a glass plate or a plastic plate. When using a plastic plate, PET, PEN, polyimide, cured acrylic resin, cured epoxy resin, cured silicone resin, various engineering plastics, cyclic polymer obtained by metathesis polymerization, etc. are mentioned, for example. Can be.

The conductive film 18 may be, for example, ITO (indium film doped with tin), FTO (tin oxide film doped with fluorine), or SnO ₂ film, but more preferably, It is a platinum film.

The pigment | dye made to adsorb | suck to the porous semiconductor layer 14 has absorption in the wavelength of 400 nm-1000 nm, For example, metal complexes, such as a ruthenium pigment and a phthalocyanine pigment, and organic pigments, such as a cyanine pigment, are mentioned.

The electrolyte (electrolyte) 22 contains iodine, lithium ions, ionic liquids, t-butylpyridine, and the like. For example, in the case of iodine, a redox body composed of a combination of iodide ions and iodine can be used. The redox agent includes a suitable solvent in which it can be dissolved.

Although the thickness of the porous semiconductor layer 14 does not specifically limit, Preferably it is 14 micrometers or more in thickness.

As one of the methods of improving the conversion efficiency of sunlight, the method of increasing the absorption efficiency of sunlight by making the thickness of a porous semiconductor layer thick is considered. However, if the electron diffusion length exceeds the thickness dimension of the porous semiconductor layer, even if the thickness of the porous semiconductor layer is further thickened, there is no effect. On the contrary, there is a problem that the opening voltage is lowered and the conversion efficiency is lowered.

In contrast, according to the dye-sensitized solar cell 10 according to the present embodiment, the electrons move easily in the porous semiconductor layer 14 through the conductive metal film 16 serving as the current collector layer, and the conductivity Since the charge transfer resistance from the metal film 16 to the electrolyte 22 is large and reverse electron transfer is unlikely to occur, high conversion efficiency is achieved even when the thickness of the porous semiconductor layer 14 is thickened to 14 μm or more, for example. Obtained. Although the upper limit of the thickness of the porous semiconductor layer 16 is suitably set according to the conversion efficiency value etc. obtained, it is about 40 micrometers, for example. It goes without saying that the present invention can be suitably applied even when the porous semiconductor layer 14 has a normal thickness.

As the semiconductor material of the porous semiconductor layer 14, for example, oxides of metals such as titanium, tin, zirconium, zinc, indium, tungsten, iron, nickel, or silver can be used. Among these, titanium oxide (titanium dioxide) This is more preferable.

The fine particles of titanium oxide include small particles having a particle diameter of 10 nm or less, large ones of about 20 to 30 nm, and the like. When the former film is made, a relatively dense film is formed. On the other hand, when the latter fine film is made, a porous film is formed. The surface of the transparent conductive film such as tin oxide has irregularities, and in order to cover the irregularities with good coverage, it is preferable to use the relatively dense porous semiconductor layer 14. For this reason, the porous semiconductor layer 14 is made into a 2-layer structure, for example, and the 1st layer by the side of a transparent conductive film is formed from the particle | grains of a titanium oxide with a small particle diameter, and the 2nd layer formed in the surface of a 1st layer has a particle diameter. It is a preferred embodiment to form the fine particles of titanium oxide larger than that of the first layer.

The conductive metal film 16 can be selected and used as long as it has a suitable conductivity. Here, the metal includes not only a metal single metal but also a metal compound and an alloy such as a metal oxide. The conductive metal film 16 may be coated with a dense oxide semiconductor, for example, titanium dioxide, on the surface of the metal.

However, from the viewpoint of reliably preventing corrosion of the conductive metal film 20 by the electrolyte 18 containing redox, such as iodine, it is more preferable to use a corrosion resistant metal.

As the corrosion resistant metals, tungsten (W), titanium (Ti) or nickel (Ni) or mixtures thereof or metal compounds thereof can be used suitably, but other than these, for example, the surface is passivated. Metals can be used.

The conductive metal film 16 can be formed on the surface of the porous semiconductor layer 16 by a simple method such as, for example, a coating method, but is preferably formed by sputtering. In addition, at this time, the edge part of the porous semiconductor layer 14 etc. are cut out by a suitable method previously, for example, and the connection part with the external electrode 26 is formed.

The thickness of the conductive metal film 16 is preferably thicker from the viewpoint of reducing the area resistance of the film, preferably 100 nm or more, and more preferably 200 nm or more. Although the upper limit of the thickness of the conductive metal film 16 is not specifically limited, For example, it is about 5 micrometers.

The conductive metal film 16 may be provided with a plurality of porous semiconductor layers interposed therebetween, that is, alternately with the porous semiconductor layer.

The formation method of the many deep hole through-holes 24 formed in the electroconductive metal film 16 is mentioned later. The through holes 24 are irregularly arranged and are formed innumerable depending on the manufacturing conditions. However, as long as the through holes 24 can penetrate and permeate the electrolyte 22 sufficiently, it is sufficient to form an appropriate number. The deep hole-shaped through hole 24 has a high diffusivity to the porous semiconductor layer 14 of the electrolyte 22 as compared to random small holes such as, for example, Non Patent Literature 1.

In the dye-sensitized solar cell according to the present embodiment, the transparent conductive film usually provided on the transparent substrate is omitted, and instead of providing a conductive metal film on the surface of the porous semiconductor layer, the conductive metal film has a deep hole shape. Since a large number of through holes are irregularly formed, the electrolyte 22 can be sufficiently penetrated and permeated through the porous semiconductor layer through the through holes, whereby the power extraction efficiency of the dye-sensitized solar cell is high, and the dye-sensitized solar cell is provided. It can be manufactured easily. Moreover, by making the thickness of a conductive metal film thick, the area resistance of a conductive metal film can be made small and it can be set as the dye-sensitized solar cell suitable for enlargement.

Here, the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment very suitable as a manufacturing method of the dye-sensitized solar cell which concerns on this embodiment is demonstrated.

The manufacturing method of the dye-sensitized solar cell which concerns on this embodiment is a microparticle layer formation process of forming the microparticle layer by arrange | positioning the microparticle which has a shape anisotropy which can be removed by heating or a solvent wash on a porous semiconductor layer; And a conductive metal film forming step of forming a conductive metal film on the fine particle layer and a fine particle layer disappearing step of disappearing the fine particle layer by heating or by solvent washing.

Hereinafter, a manufacturing example is demonstrated concretely with reference to FIG. 2A-FIG. 2D which shows a manufacturing process typically.

First, the material of the porous semiconductor layer 14 is applied to the transparent substrate 12 to form the porous semiconductor layer 14 (see FIG. 2A). Here, the porous semiconductor layer 14 refers to a material that is baked after applying the material of the porous semiconductor layer 14.

Next, the fine particles 28 having the shape anisotropy, which can be removed by heating or by solvent washing, are disposed on the porous semiconductor layer 14 to form a fine particle layer (see FIG. 2B of the particulate layer forming step).

Next, a conductive metal film 16 is formed on the fine particle layer (conductive metal film forming step, see FIG. 2C).

Next, the fine particle layer is lost by heating or by solvent washing. As a result, the through-holes 24, which are a plurality of deep holes, are irregularly formed in the conductive metal film 16 (see FIG. 2D of the particulate layer disappearing step).

Next, a dye is attached to the porous semiconductor layer.

Further, the dye-sensitized solar cell is completed by placing the substrate having the conductive film opposite to the transparent substrate, sealing with a spacer, and injecting an electrolyte solution.

In addition, as mentioned above in the description of the dye-sensitized solar cell according to the present embodiment, the conductive metal film is electrically connected to an external electrode having a suitable configuration in a suitable step.

When the fine particle layer is removed by heating, the material of the fine particle to be used is thermally decomposed at a temperature that does not thermally damage a pre-formed layer such as a porous semiconductor layer, and is burned at a temperature near the pyrolysis temperature. . The temperature which does not thermally damage the previously formed layers, such as this porous semiconductor layer, means temperature lower than 500 degreeC, for example, More preferably, it is about 200 degrees C or less. Thereby, for example, the thermal effect on the conductive metal film 16 which may occur when the conductive metal film 16 is heated at a temperature of 500 ° C. or higher is also reduced. In addition, when removing a microparticle layer by solvent washing, it uses combining the solvent which does not cause chemical damage to previously formed layers, such as a porous semiconductor layer, and the particulate material which can be easily removed by washing | cleaning using this solvent.

Although such a particulate material is not specifically limited, For example, resin, such as polystyrene and polymethyl methacrylate, and metal oxide, such as zinc oxide, can be used suitably. Moreover, the solvent used for solvent washing is not specifically limited, What is necessary is just to select suitably according to a particulate material, For example, organic solvents, such as toluene which can melt | dissolve resin, and acids, such as dilute hydrochloric acid which can melt | dissolve a metal. Can be used.

The microparticles | fine-particles formed from said material use what has shape anisotropy. As such microparticles | fine-particles, microparticles | fine-particles or needle-like microparticles | fine-particles which have many legs which make the apex of a polyhedron tip are used.

In the case of using the fine particles having a plurality of legs with the apex of the polyhedron at the tip, for example, even when the fine particles are dispersed in only one layer on the porous semiconductor layer, for example, the conductive metal film reliably penetrates the moderately thick conductive metal film formed on the fine particles. It is preferable to have the dimension of the grade which can form a hole, and although the dimension of such microparticles | fine-particles changes with the thickness of a conductive metal film, it is 1-30 micrometers, for example.

On the other hand, in the case of using needle-like fine particles, the needle-like fine particles can be formed on the porous semiconductor layer or in a linear state by being dispersed by, for example, an electronic spray method. For this reason, although the dimension of such acicular fine particles is not specifically limited, it is preferable to make it suitable length according to the thickness of a conductive metal film, and to spread so that acicular fine particles may overlap each other on a porous semiconductor layer.

By arranging the fine particles having these shape anisotropies on the porous semiconductor layer 14, deep holes are also formed in the porous semiconductor layer 14 after the fine particles are lost. Further, penetration and diffusion of the electrolyte solution inside the porous semiconductor layer 14 are performed better through this deep hole communicating with the hole penetrating the conductive metal film.

By the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment, a comparatively stable conductive metal film can be easily formed on a microparticle layer by suitable methods, such as a vapor deposition method and an application | coating method, and a microparticle layer is formed by heating etc. In the process of removal, it is possible to easily form a plurality of deep cylindrical or long cylindrical through holes irregularly disposed on the conductive metal film.

Moreover, in the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment, the porous semiconductor material and the mixed layer of microparticles | fine-particles which have a shape anisotropy which can be removed by heating or a solvent washing are formed on a porous semiconductor layer. You may comprise so that it may have a mixed layer formation process and the fine particle layer disappearance process which loses a microparticle by heating or a solvent washing | cleaning.

As a result, a conductive metal film having a large number of irregularly arranged through-holes is obtained, and the porous semiconductor material mixed with the fine particles becomes a column supporting the conductive metal after dissolving the fine particles, thus more firmly supporting the conductive metal film.

Moreover, in the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment, the mixed layer which forms the mixed layer of an electroconductive metal and microparticles | fine-particles which have a shape anisotropy which can be removed by heating or a solvent washing | cleaning on a porous semiconductor layer. You may comprise so that it may have a formation process and the fine particle layer disappearance process which loses a microparticle by heating or a solvent washing | cleaning.

As a result, a conductive metal film having a plurality of through holes formed irregularly on the surface of the porous semiconductor layer is obtained. According to this manufacturing method, since the mixed layer of electroconductive metal and microparticles | fine-particles is formed in one process, a manufacturing process is simplified.

Moreover, in the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment, you may comprise so that the porous semiconductor layer lamination process of forming a porous semiconductor layer different from a porous semiconductor layer on the surface of a conductive metal film may be carried out.

According to the manufacturing method of the dye-sensitized solar cell which concerns on this embodiment demonstrated above, since a manufacturing method is simple and many through-holes with deep depth can be reliably formed in a conductive metal film, in this embodiment, The dye-sensitized solar cell concerned can be obtained very suitably.

<Examples>

The present invention will be further described with reference to Examples and Comparative Examples. In addition, this invention is not limited to the Example demonstrated below.

(Example 1)

Titanium dioxide paste (1 layer of HT paste, 5 layers of D paste, manufactured by Solarix) was applied to the glass substrate at a thickness of 20 μm, and baked at 500 ° C. for 30 minutes to form titanium dioxide (titanium dioxide layer, porous semiconductor layer). . A tetrapod-type crystal of zinc oxide (trade name: Panatetra, 2-20 µm in maximum dimension, manufactured by Matsushita Electric Co., Ltd.) of zinc oxide was dispersed on the titanium dioxide surface of the fired substrate by an electrospray method. After that, a Ti film (Ti layer) was formed by sputtering (film thickness of 300 nm). The remaining tetrapod-type crystals were removed by rinsing with dilute hydrochloric acid. As a result, a porous Ti layer was produced.

Next, the substrate on which the Ti layer was formed was immersed in a 0.05 wt% dye solution (black die, manufactured by Solaronics Inc., acetonitrile: t-butyl alcohol = 1: 1) (20 hours).

In the counter electrode, a fluorine-doped tin oxide glass (manufactured by Solaronics Co., Ltd.) subjected to platinum sputtering was used. The substrate and the counter electrode on which the Ti layer was formed were encapsulated with a spacer having a thickness of 50 µm (Himir, Mitsui Dupont). An electrolyte solution composed of an acetonitrile solution of 40 mM of iodine, 500 mM of LiI, and 580 mM of t-butylpyridine was injected into the obtained cell to prepare a 5 mm square battery (battery cell).

The produced solar cell characteristics were irradiated with a dye-sensitized solar cell of AM 1.5 and 100 mW / cm ² using a solar simulator, and measured and evaluated. An efficiency of 10.7% was obtained.

(Example 2)

Zinc oxide crystals obtained by pulverizing zinc oxide tetrapod crystals (Panathetra, Matsushita Electric Co., Ltd.) instead of using the tetrapod type crystals (trade name: Panatetra, Matsushita Electric Co., Ltd.) as they are. A battery of 5 mm square and 50 mm square was produced in the same manner as in Example 1.

When the produced 5 mm square solar cell characteristics were evaluated by the method similar to Example 1, the efficiency of 10.7% was obtained. Moreover, the efficiency of the produced 50 mm angle was 8%, and even if it enlarged large area, the performance degradation was small.

(Comparative Example 1)

Titanium dioxide paste (1 layer of HT paste, 5 layers of D paste, made by Solarix) was applied to a transparent conductive film substrate (made by Nippon Plate Glass Co., Ltd., lowE glass) at a thickness of 20 μm, fired at 500 ° C. for 30 minutes, and then titanium dioxide ( Titanium layer, porous semiconductor layer). This substrate was immersed in 0.05 wt% of a dye solution (black die, manufactured by Solaronics Inc., acetonitrile: t-butyl alcohol = 1: 1) (20 hours). In the counter electrode, a fluorine-doped tin oxide glass (manufactured by Solaronics Co., Ltd.) subjected to platinum sputtering was used. The titanium dioxide substrate and the counter electrode were encapsulated with a spacer having a thickness of 50 μm (Hymirran, Mitsui DuPont). As the electrolyte solution, an acetonitrile solution of 40 mM of iodine, 500 mM of LiI, and 580 mM of t-butylpyridine was used.

When the produced 5 mm square solar cell characteristics were evaluated by the method similar to Example 1, the efficiency of 10.5% was obtained. Moreover, when the produced 50 mm square solar cell was produced, the efficiency was 3% and the performance fell largely by the large area.

(Example 3)

Titanium dioxide paste (P25, water / ethanol mixed solvent) was applied to a PET substrate (thickness 1 mm) at a thickness of 10 μm, and heated at 150 ° C. for 30 minutes to form titanium dioxide (titanium dioxide layer, porous semiconductor layer). A tetrapod-type crystal of zinc oxide (trade name: Panatetra, 2 to 20 µm in maximum dimension, manufactured by Matsushita Electric Works) was dispersed on the surface of the titanium dioxide by an electrospray method. Then, a Ti film was formed by sputtering (film thickness of 300 nm). The remaining zinc oxide spheres were removed by rinsing with dilute hydrochloric acid. As a result, a porous Ti layer was produced.

Next, the substrate on which the Ti layer was formed was immersed in a 0.05 wt% dye solution (black die, manufactured by Solaronics Inc., acetonitrile: t-butyl alcohol = 1: 1) (20 hours).

As a counter electrode, a titanium plate (manufactured by Solaronics Co., Ltd.) subjected to platinum sputtering was used. The substrate and the counter electrode on which the Ti layer was formed were encapsulated with a spacer having a thickness of 25 μm (Hymir, Mitsui Dupont). Into the obtained cell, an electrolyte solution composed of 40 mM of iodine, 500 mM of LiI, and 580 mM of t-butylpyridine was injected to prepare a 5 mm and 50 mm square battery.

The solar cell characteristics of the solar cell were irradiated with dye-sensitized solar cells of AM 1.5 and 100 mW / cm ² using a solar simulator, and measured and evaluated. An efficiency of 4% was obtained with respect to the battery, and even if the area was increased, the performance was low.

(Comparative Example 2)

Titanium dioxide paste (P25, water / ethanol mixed solvent) was applied to a transparent conductive film plastic PET substrate (Aldrich, surface resistance 10-20Ω / □, thickness 1mm) to a thickness of 10μm, heated at 50 ° C for 30 minutes, and titanium dioxide (Titanium dioxide layer, porous semiconductor layer) were formed. Next, the substrate was immersed in a 0.05 wt% dye solution (black die, manufactured by Solaronics, Inc., acetonitrile: t-butyl alcohol = 1: 1) (20 hours).

In the counter electrode, a fluorine-doped tin oxide glass (manufactured by Solaronics Co., Ltd.) subjected to platinum sputtering was used. The substrate (titanium dioxide substrate) and the counter electrode were sealed with a spacer having a thickness of 25 μm (Hymirran, Mitsui DuPont). Into the obtained cell, an electrolyte solution composed of 40 mM of iodine, 500 mM of LiI, and 580 mM of t-butylpyridine was injected to prepare a 5 mm and 50 mm square battery.

The produced solar cell characteristics were evaluated in the same manner as in Example 3, and the efficiency of 2.5% was obtained for a 5 mm square battery and 0.5% for a 50 mm square battery, and the performance was large due to the large area. Lowered.

(Reference Example 1)

A 5 mm square battery (battery cell) was fabricated in the same manner as in Example 1 except that polystyrene particles having a particle size of 300 nm were dispersed on the titanium dioxide surface of the fired substrate in place of the tetrapod-type crystals of zinc oxide. Was measured and evaluated. The efficiency of the obtained battery was 10.0%.

(Reference Example 2)

A 5 mm square battery was prepared in the same manner as in Example 1, except that the substrate on which the porous Ti layer was formed on the calcined titanium dioxide was heated at 500 ° C. for 30 minutes and then impregnated with a dye solution. (Battery cell) was produced and the solar cell characteristics were measured and evaluated. The efficiency of the obtained battery was 3.6%.

(Reference Example 3)

A titanium dioxide paste (1 layer of HT paste, 5 layers of D paste, manufactured by Solaronics) was applied to a glass substrate at a thickness of 20 µm, and heated at 100 ° C. for 30 minutes to form a dry titanium dioxide layer. A tetrapod-type crystal of zinc oxide (trade name: Panatetra, 2-20 µm in maximum dimension, manufactured by Matsushita Electric Co., Ltd.) of zinc oxide was dispersed on the titanium dioxide surface of the substrate by the electrospray method. Then, a Ti film (Ti layer) was formed by sputtering (film thickness of 300 nm). The remaining tetrapod-type crystals were removed by rinsing with dilute hydrochloric acid. As a result, a porous Ti layer was produced. Furthermore, the dry titanium dioxide layer was fired by heating the substrate in which the dry titanium dioxide layer and the porous Ti layer were integrated at 500 ° C. for 30 minutes.

Then, the 5 mm square battery (battery cell) was produced by the method similar to Example 1, and the solar cell characteristic was measured and evaluated. The efficiency of the obtained battery was 3.5%.

The dye adsorption state of titanium dioxide at the time of using the porous Ti electrode (porous Ti layer) of Example 1 in (A) in FIG. 3 is shown. The dye rapidly diffuses into titanium dioxide through the porous Ti electrode and is adsorbed onto the entire surface of titanium dioxide. In addition, in FIG. 3B, the pigment | dye adsorption state of the glass substrate at the time of forming a dense Ti layer on a glass substrate by the conventional method instead of a porous Ti electrode is shown. Due to the dense titanium layer, the dye can hardly pass through the Ti layer, and only a part of the glass substrate (the part scattered in an island shape in FIG. 3B) is adsorbed.

4 shows the relationship between the sheet resistance of the Ti layer formed by sputtering and the thickness of the Ti layer in Examples 1 and 2. FIG. From this, as the thickness of the Ti layer is increased, the value of the sheet resistance is greatly reduced, and when the thickness of the Ti layer is 200 nm or more, it can be seen that a low value of 10 (Ω / □) or less is obtained.

The relationship between the voltage and current density of the battery produced in Example 1 and the battery produced by the comparative example is shown in FIG. It can be seen that the battery produced in Example 1 has almost the same characteristics as the battery produced in Comparative Example.

10 dye-sensitized solar cells
12 transparent substrate
14 porous semiconductor layer
16 conductive metal film
18 conductive film
20 substrates
22 electrolyte
24 through hole
26 external electrodes
28 particulate

Claims (9)

The transparent substrate, the porous semiconductor layer which adsorb | sucked the pigment | dye arrange | positioned on the said transparent substrate, and the inside of the said porous semiconductor layer or the surface on the opposite side to the said transparent substrate are arrange | positioned, and many through-holes of a deep hole shape are irregular. A dye-sensitized aspect comprising a conductive metal film formed and electrically connected to an external electrode, and a conductive substrate provided to face the transparent substrate, and having an electrolyte between the conductive metal film and the conductive substrate. battery. The method of claim 1,
The thickness of the said conductive metal film is 100 nm or more, The dye-sensitized solar cell characterized by the above-mentioned. The method of claim 1,
The material of the said conductive metal film is a corrosion-resistant metal, The dye-sensitized solar cell characterized by the above-mentioned. The method of claim 3,
The dye-sensitized solar cell, characterized in that the corrosion-resistant metal is one or two or more or a compound thereof selected from tungsten, titanium and nickel. As a manufacturing method of the dye-sensitized solar cell of any one of Claims 1-4,
A fine particle layer forming step of disposing fine particles having shape anisotropy, which can be removed by heating or by solvent washing, on the porous semiconductor layer to form a fine particle layer,
A conductive metal film forming step of forming a conductive metal film on the fine particle layer,
A method for producing a dye-sensitized solar cell, comprising a step of disappearing a fine particle layer by heating or by solvent washing. As a manufacturing method of the dye-sensitized solar cell of any one of Claims 1-4,
A mixed layer forming step of forming a porous semiconductor material and a mixed layer of fine particles having shape anisotropy, which can be removed by heating or by solvent washing, on the porous semiconductor layer;
A conductive metal film forming step of forming a conductive metal film on the surface of the mixed layer,
A method for producing a dye-sensitized solar cell, comprising a step of disappearing a fine particle layer by heating or by solvent washing. As a manufacturing method of the dye-sensitized solar cell of any one of Claims 1-4,
A mixed layer forming step of forming a mixed layer of conductive metal and fine particles having shape anisotropy, which can be removed by heating or by solvent washing, on the porous semiconductor layer;
A method for producing a dye-sensitized solar cell, comprising a step of disappearing a fine particle layer by heating or by solvent washing. 8. The method according to any one of claims 5 to 7,
The porous semiconductor layer lamination process of forming the porous semiconductor layer different from the said porous semiconductor layer on the surface of the said conductive metal film further has a manufacturing method of the dye-sensitized solar cell characterized by the above-mentioned. The method according to any one of claims 5 to 8,
The manufacturing method of the dye-sensitized solar cell characterized by the above-mentioned microparticles | fine-particles having shape anisotropy being microparticles or needle-like microparticles | fine-particles which have many legs which make the apex of a polyhedron the tip.

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